Scientists Find Possible Second Subglacial Impact Crater in Northwest Greenland

Following the discovery of the 19.2-mile wide Hiawatha impact crater beneath the northwest margin of the Greenland Ice Sheet, Dr. Joe MacGregor of NASA’s Goddard Space Flight Center and colleagues explored satellite and aerogeophysical data in search of additional such craters and found a possible second impact crater that is 22.7 miles wide and 114 miles southeast of the Hiawatha crater.

The discovery is described in a paper in the journal Geophysical Research Letters. ..."

Following the finding of that first crater, Dr. MacGregor and co-authors checked topographic maps of the rock beneath Greenland’s ice for signs of other craters.

Using imagery of the ice surface from NASA’s Terra and Aqua satellites, they soon noticed a circular pattern some 114 miles to the southeast of Hiawatha Glacier. The same circular pattern also showed up in ArcticDEM, a high-resolution digital elevation model of the entire Arctic derived from commercial satellite imagery.

To confirm their suspicion about the possible presence of a second impact crater, the researchers studied the raw radar images that are used to map the topography of the bedrock beneath the ice, including those collected by NASA’s Operation IceBridge.

What they saw under the ice were several distinctive features of a complex impact crater: a flat, bowl-shaped depression in the bedrock that was surrounded by an elevated rim and centrally located peaks, which form when the crater floor equilibrates post-impact.

Hey, we all miss someone else’s sarcasm or intent on occasion. Not really a big deal. Peace.

21 posted on 02/13/2019 7:47:27 AM PST by Ancesthntr ("The right to buy weapons is the right to be free." A. E. van Vogt, The Weapons Shops of Isher)

22 posted on 05/27/2019 10:25:23 PM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)

"Younger Dryas" (13,000 yr bp) keyword, sorted chrono:

23 posted on 05/27/2019 10:35:26 PM PDT by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)

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